This invention relates generally to gas turbine engines and more particularly to the cleaning of gas turbine engines.
Gas turbine engines are generally required to be tested prior to final delivery to the intended customer. Prior to or during testing of the engine, it may be desirable to remove any fuel or oil residue on engine components to permit identification of any leaks that may occur during test operations. After a leak is identified and repaired, it is desirable to remove any remaining fuel and oil residue prior to shipment to the customer.
One approach to cleaning engines involves using an HCFC (hydrochlorofluorocarbon) composition, such as HCFC 141b. Another approach involves using isopropyl alcohol as a cleaning agent. Still other approaches include using steam, aqueous cleaners, hydrofluoroethers alone or mixed with other substances such as isopropyl alcohol or n-propyl bromide.
One challenge in identifying an acceptable cleaner is that the cleaner should be effective and quick acting, while meeting requirements related to environmental and safety regulations. Such requirements can include flammability, worker exposure limitations, and air and water pollution standards. For instance, the cleaning composition should be nonflammable in use on hot engine surfaces. Additionally, it is desirable to provide an effective cleaning composition which is non-ozone depleting and has a low global warming potential. Water and detergent cleaning compositions have been proposed to provide cleaning effectiveness while meeting safety and environmental requirements. However, such water based compositions have the disadvantage that water does not evaporate quickly, and water based compositions may enter electrical/electronic components on the engine, especially if the water is sprayed under pressure.
Accordingly, it would be desirable to provide a composition and method for cleaning gas turbine engines with improved effectiveness and which also meets requirements related to environmental and safety issues, and which does not pose a potential threat to electrical/electronic components of the gas turbine engine.